Accident Summary
On March 17, 2009, about 1526 mountain daylight time, a Gates Learjet Corporation Learjet 55 airplane, registered as C-GCIL, was substantially damaged during an aborted takeoff at Natrona County International Airport (CPR) in Casper, Wyoming. The airplane was operated by Sunwest Aviation LTD. of Calgary, Alberta, Canada, under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan was filed for the cross-country flight to Lafayette, Louisiana. The captain, first officer (who was flying), and two passengers were not injured.
Initial Takeoff and First Abort
The first takeoff was initiated on runway 3, a 10,165-foot long asphalt runway. About one-third of the way down the runway, between 60 and 100 knots, the tower controller advised that he thought he saw smoke coming from the left engine. The captain called for an aborted takeoff, and the first officer initiated the abort sequence, using normal braking and thrust reverser deployment for a few seconds, then continuing with thrust reversers only. The airplane exited the runway onto taxiway Alpha 6. The flight crew performed an engine power check with no anomalies noted. They then taxied back to Alpha 1 via taxiway Alpha. The captain reported no reason to suspect hot brakes due to minimal brake use and elected to taxi for another takeoff. After a taxi time of 4 to 5 minutes, the first officer conducted a second takeoff.
Second Takeoff and Second Abort
During the second takeoff roll on runway 3, between 80 knots and prior to the V1 call, the flight crew heard and felt a bang as the airplane yawed to the right. The captain called for a second aborted takeoff. As the first officer initiated the abort, a second bang and additional yaw occurred. The captain took control, maintaining directional control with reverse thrust and nose wheel steering. The airplane was slowed and exited onto taxiway Alpha 7. Upon opening the cabin door, the crew observed a fire near the left main landing gear and immediately evacuated. Airport Fire and Rescue arrived shortly and extinguished the fire.
Investigation Findings
Examination by a Federal Aviation Administration (FAA) inspector revealed fire damage to the left main landing gear and a punctured hole in the right side of the fuselage just aft of the cockpit. The Casper Airport Public Safety Department found tire debris extending from taxiway Alpha 4 to Alpha 7. The Cockpit Voice Recorder (CVR) captured 31 minutes and 56 seconds of usable audio. The recording showed that about 16 minutes after power application, the crew began preparing for flight. During the first takeoff, about 8 seconds after the first officer responded to the captain's "eighty knots" call, the tower controller transmitted that a lot of smoke appeared to be coming from the engine. The captain called for a rejected takeoff at 23 minutes 28 seconds; 37 seconds later, the first officer remarked that the right brake felt funny. After the first abort, the captain decided to run up both engines. At 24 minutes 45 seconds, the tower controller noted that the smoke appeared to be from the left engine. At 27 minutes 18 seconds, the captain stated both engines were pulling full power and commented it was not a high-speed abort as the aircraft was only through ninety knots. The second takeoff clearance was given at 28 minutes 34 seconds. Two loud noises, about one second apart, were heard beginning at 29 minutes 34 seconds; the captain called for a rejected takeoff, and the first officer said "blew a tire."
The flight crew reported the airplane weight at 20,772 pounds. According to the Learjet 55 Aircraft Flight Manual (AFM), Section 5, the maximum landing weight (design structural limit) is 17,000 pounds. A Bombardier Learjet representative calculated the maximum brake energy weight for the accident conditions (temperature 48°F, altitude 5,530 feet, wind from 030 degrees at 5 knots, runway 3 with 0.1% gradient) as 20,300 pounds. The AFM Section 3 states that if a rejected takeoff is made at a weight above the landing maximum brake energy weight, a High Energy Stop Inspection is required. Additionally, Section 1 contains turn-around limits: if the brake energy limit is exceeded, a 30-minute parking period and visual inspection of main gear tires, wheels, and brakes are required before the next takeoff. The operator reported that the accident airplane was equipped with modification AAK 55-82-6, which made the 30-minute waiting period inapplicable.
Probable Cause
The investigation report did not state a probable cause.